2.9.Â Troubleshooting

This section covers basic installation
troubleshooting, such as common problems people have
reported.

Check the Hardware Notes (https://www.freebsd.org/releases/index.html)
document for the version of FreeBSD to make sure the hardware is
supported. If the hardware is supported and lock-ups or other
problems occur, build a custom kernel using the instructions in
ChapterÂ 8, Configuring the FreeBSD Kernel to add support for devices which
are not present in the GENERIC kernel. The
default kernel assumes that most hardware devices are in their
factory default configuration in terms of
IRQs, I/O addresses, and
DMA channels. If the hardware has been
reconfigured, a custom kernel configuration file can tell FreeBSD
where to find things.

Note:

Some installation problems can be avoided or alleviated by
updating the firmware on various hardware components, most
notably the motherboard. Motherboard firmware is usually
referred to as the BIOS. Most motherboard
and computer manufacturers have a website for upgrades and
upgrade information.

Manufacturers generally advise against upgrading the
motherboard BIOS unless there is a good
reason for doing so, like a critical update. The upgrade
process can go wrong, leaving the
BIOS incomplete and the computer
inoperative.

If the system hangs while probing hardware during boot, or
it behaves strangely during install, ACPI may
be the culprit. FreeBSD makes extensive use of the system
ACPI service on the i386,
amd64, and ia64 platforms to aid in system configuration
if it is detected during boot. Unfortunately, some bugs still
exist in both the ACPI driver and within
system motherboards and BIOS firmware.
ACPI can be disabled by setting the
hint.acpi.0.disabled hint in the third stage
boot loader:

set hint.acpi.0.disabled="1"

This is reset each time the system is booted, so it is
necessary to add hint.acpi.0.disabled="1" to
the file /boot/loader.conf. More
information about the boot loader can be found in SectionÂ 12.1, “Synopsis”.